An information transmitting mechanism is described for transmitting information of an ink tank of an ink jet recording apparatus to a controller thereof. The recording apparatus performs recording by scanning a carriage on which a recording head and the ink tank are mounted; the ink tank is removably mounted to said recording head. The information transmitting mechanism includes the ink tank and the recording head; in particular, the ink tank has an information mark. The recording head is connected to the ink tank and has a signal terminal making a signal connection with the ink tank and with the controller of the apparatus. The content of the information mark is transmitted to the controller through the signal terminal. The information relating to the ink tank is transmitted to the controller through the head terminal and through the carriage terminal. The information relating to the recording head is transmitted to the controller through the carriage terminal.